Update MSDOSFS code using NetBSD's msdosfs as a guide to support

FAT32 partitions.  Unfortunately, we looked around here at
Walnut Creek CDROM for any newer FAT32-supporting versions
of Win95 and we were unsuccessful; only the older stuff here.
So this is untested beyond simply making sure it compiles and
someone with access to an actual FAT32 fs will have
to let us know how well it actually works.
Submitted by:	Dmitrij Tejblum <dima@tejblum.dnttm.rssi.ru>
Obtained from:	NetBSD

1 files changed, 88 insertions, 57 deletions

diff --git a/sys/fs/msdosfs/msdosfsmount.h b/sys/fs/msdosfs/msdosfsmount.h
index 49a9327..3a0ee6e 100644
--- a/sys/fs/msdosfs/msdosfsmount.h
+++ b/sys/fs/msdosfs/msdosfsmount.h
@@ -1,9 +1,9 @@
-/*	$Id: msdosfsmount.h,v 1.11 1997/03/03 17:36:11 bde Exp $ */
-/*	$NetBSD: msdosfsmount.h,v 1.7 1994/08/21 18:44:17 ws Exp $	*/
+/*	$Id: msdosfsmount.h,v 1.12 1997/10/12 20:25:02 phk Exp $ */
+/*	$NetBSD: msdosfsmount.h,v 1.17 1997/11/17 15:37:07 ws Exp $	*/
 
 /*-
- * Copyright (C) 1994 Wolfgang Solfrank.
- * Copyright (C) 1994 TooLs GmbH.
+ * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
+ * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
  * All rights reserved.
  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
  *
@@ -63,121 +63,131 @@ MALLOC_DECLARE(M_MSDOSFSMNT);
 struct msdosfsmount {
 	struct mount *pm_mountp;/* vfs mount struct for this fs */
 	dev_t pm_dev;		/* block special device mounted */
-	uid_t pm_mounter;	/* uid of the user who mounted the FS */
 	uid_t pm_uid;		/* uid to set as owner of the files */
 	gid_t pm_gid;		/* gid to set as owner of the files */
 	mode_t pm_mask;		/* mask to and with file protection bits */
 	struct vnode *pm_devvp;	/* vnode for block device mntd */
 	struct bpb50 pm_bpb;	/* BIOS parameter blk for this fs */
+	u_long pm_FATsecs;	/* actual number of fat sectors */
 	u_long pm_fatblk;	/* block # of first FAT */
-	u_long pm_rootdirblk;	/* block # of root directory */
+	u_long pm_rootdirblk;	/* block # (cluster # for FAT32) of root directory number */
 	u_long pm_rootdirsize;	/* size in blocks (not clusters) */
 	u_long pm_firstcluster;	/* block number of first cluster */
 	u_long pm_nmbrofclusters;	/* # of clusters in filesystem */
 	u_long pm_maxcluster;	/* maximum cluster number */
 	u_long pm_freeclustercount;	/* number of free clusters */
-	u_long pm_bnshift;	/* shift file offset right this amount to get a block number */
-	u_long pm_brbomask;	/* and a file offset with this mask to get block rel offset */
 	u_long pm_cnshift;	/* shift file offset right this amount to get a cluster number */
 	u_long pm_crbomask;	/* and a file offset with this mask to get cluster rel offset */
+	u_long pm_bnshift;	/* shift file offset right this amount to get a block number */
 	u_long pm_bpcluster;	/* bytes per cluster */
-	u_long pm_depclust;	/* directory entries per cluster */
 	u_long pm_fmod;		/* ~0 if fs is modified, this can rollover to 0	*/
 	u_long pm_fatblocksize;	/* size of fat blocks in bytes */
 	u_long pm_fatblocksec;	/* size of fat blocks in sectors */
 	u_long pm_fatsize;	/* size of fat in bytes */
+	u_long pm_fatmask;	/* mask to use for fat numbers */
+	u_long pm_fsinfo;	/* fsinfo block number */
+	u_long pm_nxtfree;	/* next free cluster in fsinfo block */
+	u_int pm_fatmult;	/* these 2 values are used in fat */
+	u_int pm_fatdiv;	/*	offset computation */
+	u_int pm_curfat;	/* current fat for FAT32 (0 otherwise) */
 	u_int *pm_inusemap;	/* ptr to bitmap of in-use clusters */
-	char pm_ronly;		/* read only if non-zero */
-	char pm_waitonfat;	/* wait for writes of the fat to complete, when 0 use bdwrite, else use bwrite */
+	u_int pm_flags;		/* see below */
 	struct netexport pm_export;	/* export information */
 };
+/* Byte offset in FAT on filesystem pmp, cluster cn */
+#define	FATOFS(pmp, cn)	((cn) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv)
+
+
+#define	VFSTOMSDOSFS(mp)	((struct msdosfsmount *)mp->mnt_data)
 
 /* Number of bits in one pm_inusemap item: */
 #define	N_INUSEBITS	(8 * sizeof(u_int))
 
 /*
- * How to compute pm_cnshift and pm_crbomask.
- *
- * pm_crbomask = (pm_SectPerClust * pm_BytesPerSect) - 1
- * if (bytesperclust == * 0)
- * 	return EBADBLKSZ;
- * bit = 1;
- * for (i = 0; i < 32; i++) {
- *	if (bit & bytesperclust) {
- *		if (bit ^ bytesperclust)
- *			return EBADBLKSZ;
- *		pm_cnshift = * i;
- *		break;
- *	}
- *	bit <<= 1;
- * }
- */
-
-/*
  * Shorthand for fields in the bpb contained in the msdosfsmount structure.
  */
 #define	pm_BytesPerSec	pm_bpb.bpbBytesPerSec
-#define	pm_SectPerClust	pm_bpb.bpbSecPerClust
 #define	pm_ResSectors	pm_bpb.bpbResSectors
 #define	pm_FATs		pm_bpb.bpbFATs
 #define	pm_RootDirEnts	pm_bpb.bpbRootDirEnts
 #define	pm_Sectors	pm_bpb.bpbSectors
 #define	pm_Media	pm_bpb.bpbMedia
-#define	pm_FATsecs	pm_bpb.bpbFATsecs
 #define	pm_SecPerTrack	pm_bpb.bpbSecPerTrack
 #define	pm_Heads	pm_bpb.bpbHeads
 #define	pm_HiddenSects	pm_bpb.bpbHiddenSecs
 #define	pm_HugeSectors	pm_bpb.bpbHugeSectors
 
 /*
- * Map a cluster number into a filesystem relative block number.
+ * Convert pointer to buffer -> pointer to direntry
  */
-#define	cntobn(pmp, cn) \
-	((((cn)-CLUST_FIRST) * (pmp)->pm_SectPerClust) + (pmp)->pm_firstcluster)
+#define	bptoep(pmp, bp, dirofs) \
+	((struct direntry *)(((bp)->b_data)	\
+	 + ((dirofs) & (pmp)->pm_crbomask)))
 
 /*
- * Map a filesystem relative block number back into a cluster number.
+ * Convert block number to cluster number
  */
-#define	bntocn(pmp, bn) \
-	((((bn) - pmp->pm_firstcluster)/ (pmp)->pm_SectPerClust) + CLUST_FIRST)
+#define	de_bn2cn(pmp, bn) \
+	((bn) >> ((pmp)->pm_cnshift - (pmp)->pm_bnshift))
 
 /*
- * Calculate block number for directory entry in root dir, offset dirofs
+ * Convert cluster number to block number
  */
-#define	roottobn(pmp, dirofs) \
-	(((dirofs) / (pmp)->pm_depclust) * (pmp)->pm_SectPerClust \
-	+ (pmp)->pm_rootdirblk)
+#define	de_cn2bn(pmp, cn) \
+	((cn) << ((pmp)->pm_cnshift - (pmp)->pm_bnshift))
 
 /*
- * Calculate block number for directory entry at cluster dirclu, offset
- * dirofs
+ * Convert file offset to cluster number
  */
-#define	detobn(pmp, dirclu, dirofs) \
-	((dirclu) == MSDOSFSROOT \
-	 ? roottobn((pmp), (dirofs)) \
-	 : cntobn((pmp), (dirclu)))
+#define de_cluster(pmp, off) \
+	((off) >> (pmp)->pm_cnshift)
 
 /*
- * Convert pointer to buffer -> pointer to direntry
+ * Clusters required to hold size bytes
  */
-#define	bptoep(pmp, bp, dirofs) \
-	((struct direntry *)((bp)->b_data)	\
-	 + (dirofs) % (pmp)->pm_depclust)
-
+#define	de_clcount(pmp, size) \
+	(((size) + (pmp)->pm_bpcluster - 1) >> (pmp)->pm_cnshift)
 
 /*
- * Convert filesize to block number
+ * Convert file offset to block number
  */
 #define de_blk(pmp, off) \
-	((off) >> (pmp)->pm_cnshift)
+	(de_cn2bn(pmp, de_cluster((pmp), (off))))
 
 /*
- * Clusters required to hold size bytes
+ * Convert cluster number to file offset
  */
-#define	de_clcount(pmp, size) \
-	(((size) + (pmp)->pm_bpcluster - 1) >> (pmp)->pm_cnshift)
+#define	de_cn2off(pmp, cn) \
+	((cn) << (pmp)->pm_cnshift)
+
+/*
+ * Convert block number to file offset
+ */
+#define	de_bn2off(pmp, bn) \
+	((bn) << (pmp)->pm_bnshift)
+/*
+ * Map a cluster number into a filesystem relative block number.
+ */
+#define	cntobn(pmp, cn) \
+	(de_cn2bn((pmp), (cn)-CLUST_FIRST) + (pmp)->pm_firstcluster)
+
+/*
+ * Calculate block number for directory entry in root dir, offset dirofs
+ */
+#define	roottobn(pmp, dirofs) \
+	(de_blk((pmp), (dirofs)) + (pmp)->pm_rootdirblk)
+
+/*
+ * Calculate block number for directory entry at cluster dirclu, offset
+ * dirofs
+ */
+#define	detobn(pmp, dirclu, dirofs) \
+	((dirclu) == MSDOSFSROOT \
+	 ? roottobn((pmp), (dirofs)) \
+	 : cntobn((pmp), (dirclu)))
 
 int msdosfs_init __P((struct vfsconf *vfsp));
+int msdosfs_mountroot __P((void));
 
 #endif /* KERNEL */
 
@@ -190,6 +200,27 @@ struct msdosfs_args {
 	uid_t	uid;		/* uid that owns msdosfs files */
 	gid_t	gid;		/* gid that owns msdosfs files */
 	mode_t	mask;		/* mask to be applied for msdosfs perms */
+	int	flags;		/* see below */
+	int magic;		/* version number */
 };
 
+/*
+ * Msdosfs mount options:
+ */
+#define	MSDOSFSMNT_SHORTNAME	1	/* Force old DOS short names only */
+#define	MSDOSFSMNT_LONGNAME	2	/* Force Win'95 long names */
+#define	MSDOSFSMNT_NOWIN95	4	/* Completely ignore Win95 entries */
+#ifndef __FreeBSD__
+#define	MSDOSFSMNT_GEMDOSFS	8	/* This is a gemdos-flavour */
+#endif
+/* All flags above: */
+#define	MSDOSFSMNT_MNTOPT \
+	(MSDOSFSMNT_SHORTNAME|MSDOSFSMNT_LONGNAME|MSDOSFSMNT_NOWIN95 \
+	 /*|MSDOSFSMNT_GEMDOSFS*/)
+#define	MSDOSFSMNT_RONLY	0x80000000	/* mounted read-only	*/
+#define	MSDOSFSMNT_WAITONFAT	0x40000000	/* mounted synchronous	*/
+#define	MSDOSFS_FATMIRROR	0x20000000	/* FAT is mirrored */
+
+#define MSDOSFS_ARGSMAGIC	0xe4eff300
+
 #endif /* !_MSDOSFS_MSDOSFSMOUNT_H_ */